Lubricant compositions of high film strength



Patented May 24, 1938 UNITED STATES LUBRICANT COMPOSITIONS OF HIGH FILM STRENGTH William J. Msnhand Joseph A. Spina. Niagara Falls, N. Y., assilnors to Hooker Electrochemical Company, New York, N. Y., a corporation of New York No Dra riginal application June 5, 1986,

wing. Serial No. 83,781. Divided and this application March 18. 1937, Serial No. 181,748

18 Claims.

It is known that various halogenated and more particularly chlorinated hydrocarbons, when added to mineral lubricating oils, have the property of increasing film strength. Among the available hydrocarbons, those of the aliphatic series, when chlorinated, have good film strengthening properties and are very soluble in or miscible with lubricating oils. These chlorinated aliphatic hydrocarbons are, however, not suillciently stable for use under high temperature conditions, such as those met with in automobile crank cases. Under such conditions the chlorinated aromatic hydrocarbons are preferred on account of their greater heat stability. These latter have, however, in general, a relatively low solubility in mineral lubricating oils, a circumstance which limits the percentage of chlorine which can be introduced into the oil in combination with these materials. I

Among the chlorinated aromatic hydrocarbons that have been used are chlor-naphthalenes and chlor-diphenyls. These materials, besides having a limited solubility, are open to the further objection that they are expensive. The chlor- 25 benzenes are satisfactory from the point of view of cost, but for various practical reasons only the tetrachlor and hexachlor have hitherto been available and these are unsatisfactory from the point of view of solubility. In co-pending application Serial No. 76,661 filed April 27, 1936 we several degrees. We therefore call it our "low solidification-point chlor-benzene or "L. S. P. chlor-benzene." While monochlor-benzene and some of the isomers of dichlorand trichlor-benzene are of satisfactory solubility these are too volatile to have any practical value. The particular merit of our low solidification point chlorbenrene is that it has a satisfactory solubility without being volatile.

We have discovered and disclosed in co-pending application Serial No. 83,731, filed June 5, 1936, of which this present application is a division, that many other chlorinated hydrocarbons form not only low solidification point mixtures, but in some cases true eutectics, not only with the chlor-benzenes but with each other. It seems to be a further characteristic that low melti temperature is a concomitant of high solubility in mineral oils. We shall refer to these mixtures as high'solubility mixtures, it being understood that by this expression is meant mixtures of chlorinated hydrocarbons of high solubility in mineral oils relative to the solubility of the components of the mixture.

Thus we have found that tetrachlor-benzene as well as our low solidification point chlor-benzene form such low-melting, high-solubility mixtures with chlor-naphthalenes, chlor-diphenyls and many other chlorinated hydrocarbons.

The following table gives the melting points of 30 have disclosed a process for production of a spevarious mixtures of the materials described:

' Melt- Melt- Melt- Component ing Component ing Pemnt if we we new. 85

, G m C'eniicm!- W grade grade Okla-naphthalene 75 Teirachlor-benmne 138 84 Chlor-napli 128 50 L. S. P. chlor-bensone 94 60 62 0 Ohlor-dipbanyl 163 36 L'. S. P. chlor-benscnm, 94 65 78 56 %chlorine. 68% chlorine.

cial mixture of chlor-benzenes which is characterized not only by a low melting temperature but 46 also by high solubility in lubricating oils. This 7 mixture is not a blend but is naturally formed during the process of chlorination and consists principally of the isomers of 'tetrachlor benzene, together with pentachlor and hexachlor-benzene. so It is not a eutectic but is mushy over a range of approximate those which give the lowest melting points. With a little more care in determining the critical proportions, it is believed that true eutectics could be obtained. However, we do not wish to be limited to eutectic mixtures since any increase in solubility is a useful result. Moreover, in incorporating these waxy chlorinated by- In the foregoing table the proportions givendrocarbons with mineral lubricating base oils it is customary. if not practically necessary, to raise the temperature of the oil above the melting point of the waxy hydrocarbon. The relatively low melting point of our mixture therefore greatly facilitates the blending of these materials with the base oils. Thus, it will be seen that in every case the melting point of the mixture is from 40' C. to 85' C. lower than that of either component and well below the temperature of low pressure steam. These temperatures are therefore very much easier to attain in the oil refinery than those which have heretofore been necessary in blending high film-strength lubricants.

The limit of solubility of these film-strengthening agents in oils is considered to be the percentage that remains in solution at 1". or that redissolves when the oil is brought back to room temperature. The solubility of the various mixtures mention above, as determined in this way, in mineral lubricating oil having a Saybolt viscosity of 230 seconds at 100 F. is as follows:

( By weight, in ran/o 1. oil, based on the oil.

It will therefore be seen from the above table that through our invention the percentage of chlorine that may be introduced into lubricating oils in chemical combination with aromatic hydrocarbons may be more than doubled. At the same time, because of the relative cheapness of the materials that are thus made available, the cost of the lubricant may be reduced. This greatly widens the scope of usefulness of such compounds. Moreover, by means of such combinations as those described above and others too numerous to mention, the technical properties of the lubricant itself may be improved.

We do not wish to be limited to the specific materials listed as it is obviously impossible to discuss allthe possible chlorinated hydrocarbons which in various combinations will form useful mixtures of low melting point and high solu-- bility.

It will likewise be obvious that the several components of our high solubility mixtures may be dissolved in the mineral lubricating oil separately. In that case the advantage of lowered melting point which results from premixing the comused to the limit of their respective solubillties.

but also when used in like proportions. This will be illustrated by the following tests on Lever load Lever load Oil not withwiihstood and Pound: Pounds Bass oil (Penns lvanla S. A. E. 90) l0 Base oil plus 2 7 istrachlor'benuuen 40 Bass oil plus 2% hexachlor-bcnune. 40 46 Base oil plus 2 chlor-naphthalene 46 50 Base oil plus 2 a L. S. P. chior-benzene.. Bass oil plus 25% chlor-nsphtbaiene- L. B. P. chlor-benseue eutectic 60 Base oil us 5% L. 8. I. chlor-benzene Base oi plus 6% chlor-naphthslene- L. S. P. chlor-beuzeno eutectic 00 as Base oil plus 36%! L. B. P. chlor-benzene. 00 65 Base oil plus 752% chior-naphthalene- L. 8. P. chlornuns eutectic M I Limit of solubility.

In the Timken machine the bearing is between a shaft and a flat block, giving line contact. The pressure or "load is applied by hanging weights upon the end of a lever through which the welsht is transferred to the bearing. The test is that the oil shall carry the load for ten minutes without seizure or scoring of the surfaces. After a successful test a brightly polished line of contact will be found. The width of this can be measured and the intensity of pressure thus determined, but for purpose of comparison this is not necessary.

These tests show that 2%% of tetrachlorbenzene (limit of solubility) increases the filmstrength 3% times, 2%% of'hexachlor-benzene (limit of solubility) 4 times, 2 of chlor-naphthalene 4% times, 2 of L S. P. chlor-benzene 4% times, 2 of chlor-naphthaiene L. S. P. chior-benzene eutectic 5 times, 5% of L. B. P. chlor-benzene 6 times, 5% of chlor-naphthalene-L. S. P. chlor-benzene eutectic 6 times,

l /2% L. S. P. chior-benzene (limit of solubility) 6 times and 7 /z% of chlor-naphtha ene- L. B. P. chlor-benzene eutectic 6% times. is an unexpected result, as the chlor-naphthalene- L. S. P. chlor-benzene contains only 62.3% chlorine, as compared with 65.7% in the case oi the tetrachlor-benzene, 68.6% in the case of the mixtures is increased beyond the limits of solubility of its separate ingredients the load carried by the oil is still further increased. Thus our product shows a greater effectiveness than that of its separate ingredients both by reason of some inherent unpredictable property and also by reason of its greater solubility.

Wherever in the claims the word solid" occurs, it is to be understood that solid at the upper limit of atmospheric temperature is meant. Whenever the solubility in mineral, oil is given, it is to be understood as having been determined by the freeze 'test hereinbefore described. In the claims the expression simple carbon ring structure" is intended to exclude carbon ring compounds complicated by side chains. such as aliphatic groups, which affect the solubility and heat-stability of the compound, also those, hav- 'ing oxygen groups, which are not considered to be hydrocarbons. The expression non-volatile" means non-volatile for practical purposes under the conditions of use in the crank case of internal combustion engines.

We claimasourinventionz- 1. A lubricant composition of relatively high oil-film strength comprising a major proportion of mineral lubricating oil and in stable solution therein a minor proportion of a substantially eutectic mixture having relatively low melting point and high solubility in said oil and comprising substantially neutral and non-volatile, normally solid, oil-mm strengthening halogenated hydrocarbons of simple carbon ring structure having relatively high melting points and low solubilities in said oil.

2. A lubricant composition of relatively high oil-film strength comprising a major proportion oi mineral lubricating oil and in stable solution therein a minor proportion 01' a substantially eutectic mixture having a relatively low melting point and high solubility in said oil and comprising substantially neutral and non-volatile normally solid, oil-film strengthening chlorinated hydrocarbons or simple carbon ring structure having relatively high melting points and low solubilities in said oil.

3. A lubricant composition of relatively high oil-film strength comprising a major proportion of a mineral lubricating oil and in stable solution therein a minor proportion of a substantially eutectic mixture having a relatively low melting point and high solubility in said oil and comprising substantially neutral and non-volatile normally solid, oil-film strengthening chlorinated hydrocarbons of simple carbon ring structure having relatively high melting points and low solubilities in said oil, at least one of said chlorinated hydrocarbons having a greater solubility in said oil as a part of said mixture than by itself:

4. A lubricant composition of relatively high oil-film strength comprising a major proportion of mineral lubricating oil and in stable solution therein a minor proportion of a substantially eutectic mixture of substantially neutral and nonvolatile solid chlor-napht'halene and tetrachlorbenzene.

5. A lubricant composition of relatively high oil-film strength comprising a major proportion of mineral lubricating oil and in stable solution therein a minor proportion of a substantially eutectic mixture or substantially neutral, normally solid chlor-naphthalene and chlor-benzenes above trichlor-benzene having relatively high melting points and low solubilities in said oil.

6. A lubricant composition of relatively high oil-film strength comprising a major proportion of a mineral lubricating oil and in stable solution therein a minor proportion of a mixture melting at substantially 84 C. and having a solubility of substantially 12% in said oil consisting substantially as to 75% of chlor-naphthalene melting at about 128 C. and having a solubility of about 9% in said oil and as to the remainder of tetrachlor-benzene melting at about 138 C. and having a solubility 01 about 2% in said oil.

'7. A lubricant composition 01' relatively high oil-film strength comprising a major proportion of a mineral lubricating oil in stable solution therein and a minor proportion of a mixture melting at substantially 62 C. and having a solubility of substantially 18% in said 011, consisting substantially as to 50% of chlor-naphthalene melting at about 128 C. and having a solubility of about 9% in said oil and as to the remainder of a mixture of tetrachlor-benzene isomers, pentachlor-benzene and hexachlor-benzene melting at about 94 C. and having a solubility of about 7% in said oil.

8. A lubricant composition of relatively hi h oil-film strength comprising a major proportiim of mineral lubricating oil and in stable solution therein a minor proportion of a substantially eutectic mixture of substantially neutral. normally solid chlor-diphenyl and chlor-benssnes above trichlor-benzene having relatively high melting points and low solubilities in said oil.

9.'A lubricant composition oi relatively high oil-film strength comprising a major proportion of mineral lubricating oil and a minor proportion of a mixture melting at substantially '18 C. and having a solubility of substantially 11% in said oil consisting substantially as to of chlordiphenyl melting at about 163 C. and having a solubility of about 7% in said oil and as to the remainder of a mixture of tetrachlor-benzene isomers, pentachlor-benzene and hexachlorbenzene, melting at about 94 C. and having a solubility of about 7% in said oil.

10. A lubricant composition of relatively high oil-film strength comprising a major proportion of mineral lubricating oil and in stable solution therein a minor proportion of substantially neutral and non-volatile normally solid, oil-film strengthening halogenated hydrocarbons of simple carbon ring structure having relatively high melting points and low solubilities in said oil but forming together a eutectic mixture of relatively low melting point and high solubility in said oil, said halogenated hydrocarbons being present in said composition in substantially eutectic proportions.

11. A lubricant composition oi! relatively high oil-film strength comprising a major proportion of mineral lubricating oil and in stable solution therein a minor proportion of substantially neutral and non-volatile, normally solid, oil-film strengthening chlorinated hydrocarbons of simple carbon ring structure having relatively high melting points and low soiubilities in said oil but forming together a eutectic mixture of relative- 1y iow melting point and high solubility in said 011, said chlorinated hydrocarbons being present in said composition in substantially eutectic proportions.

12. A lubricant composition of relatively high oil-film strength comprising major proportion of mineral lubricating oil and in stable solution therein a minor proportion oi substantially neutral and non-volatile, normally solid oil-film strengthening halogenated hydrocarbons of simple carbon ring structure having relatively high melting points and low solubilities in said oil but forming together a eutectic mixture of relatively low melting point and high solubility in said oil, said halogenated hydrocarbons being present in said composition in substantially eutectic proportions, at least one of said halogenated hydrocarboris having a greater solubility in said oil in presence of another of said hydrocarbons than by itself.

13. A lubricant composition of relatively high oil-film strength comprising a major proportion of mineral lubricating oil and in stable solution therein a minor proportion of substantially neutral and non-volatile normally solid chlor-naphthalene and tetrachlor-benzene in substantially eutectic proportions.

14. A lubricant composition of relatively high oil-film strength comprising a major proportion of mineral lubricating oil and in stable solution therein a minor proportion of substantially neueutectic proportions.

trai. normally solid chlor-naphthalene and chlorbsnssnss above, trichlorbensene in substantially it. A lubricant composition oi relatively high oil-iilm strength comprising a major proportion of mineral lubricating oil and in stable solution therein a minor proportion 01 chlor-naphthalens melting at substantially 128' C. and having a solubility of substantially 9 per cent in said oil and tetrachlor-bensene melting at substantially 188 C. and having a solubility of substantially Iper cent in said oil, said chlor-naphthalene and 'tetrachlor-bensene being present in said composition in the proportions oi substantially 3 parts oi said chlor-naphthalene to 1 part of said tetrachlor-bensene by weight. I

16. A lubricant composition of relatively high oil-iiim strength comprising a major proportion oi mineral lubricating oil and in stable solution therein a minor proportion of chlor-naphthalene melting at substantially 138' C. and having a solubility of substantially 9 per cent in said oil and a mixture of tetrachlor-benzene isomers, pentachlor-benzene and hexachlor-benzene melting at substantially 94 C. and having a solubility of substantially 'I per cent in said 011, said chlornaphthalene and chlor-benzene mixture being present in said composition in the proportions of substantially 1 partoi said chlor-naphthalene to 1 part 0! said chlor-benzene mixture by weight.

ll .a' lubricant composition oi relatively high oll-iilm strength comprising a major proportion of mineral lubricating oil and in stable solution therein a minor proportion of substantially neutral normally solid chlor-diphenyl and chlor-benlenes above trichlor-bensene in substantially eutectic proportions.

18. A lubricant composition of relatively high oil-film strength comprising a major proportion 01 mineral lubricating oil and in stable solution therein a minor proportion of chlor-diphenyl melting at substantially 168' C. and having a solubility in said oil of substantially 7 per cent and a mixture oi tetrachlor-bensene isomers. pentachlor-bcnzene and hexachlor-benzene melting at substantially 94'. C. and having a solubility of 'l per cent in said oil, said chlor-diphenyl and chlor-benzene mixture being present in said com- Position in the proportion of'substantially 3% parts of said chlor-diphenyl to 6 parts of said chlor-benzene mixture by weight.

WILLIAM J. MARSH. JOSEPH A. SPINA. 

